Little can be added to the informative reviews preceding this one. Want to add ny voice to the chorus: great music and animation, kudos to the Fleischers.

You see Cab Calloway and his orchestra caricatured a lot in these old cartoons, but this is the real deal. Cab was really hot at this time and you see and hear him in all his glory. Be sure to check out Minnie The Moocher and Snow White for more Cab Calloway!

This early version of a music video is great. Betty decides to see what all the fuss is about about the old man and learns he's a swinger. Did anyone else notice the other lady coming down the mountain had three kids by him?

This film is notable enough that Wikipedia has an article on it. Here are a few points from it, and a few of my own:
Cab Calloway's orchestra performed all of the music in the film. Cab sang three songs (possibly written for the film?), and voiced all the characters except Betty, who was voiced by Mae Questel. He also provided the live action reference for the Old Man's dance routine in the cave scene. Max Fleischer invented the first device to enable the use of live action references in animation, which he named the Rotoscope, in 1915.
In the cave scene, Betty asks "Whatcha gonna do now?" to which the Old Man replies, "Gonna do the best I can!" This scene inspired Tim Burton's confrontation scene between Oogie Boogie and Santa Claus in The Nightmare Before Christmas. The above dialog was included almost verbatim, the music was very similar to Minnie the Moocher, and Oogie's dance steps are close to Cab's.
Before enforcement of the Hays Code began in 1934, Betty was styled as a "Jazz Baby" flapper who looked and sang like Helen Kane and expressed the sexuality of Clara Bow. She had as a close friend and companion an anthropomorphic dog named Bimbo. Following enforcement of the Code, Betty became a domesticated single career girl, wore modest clothing, abandoned jazz and swing, and traded in Bimbo for a non-anthropomorphic dog named Pudgy. She also acquired a wholesome and fun-loving grandfather. Comments about and comparisons between pre- and post-Code Fleischer cartoons are frequently to be found in the reviews here on IA.
However, The Wikipedia article for this film, in quoting and paraphrasing author Christopher P. Lehman, identifies it specifically as the Fleischer Studios film that provoked enough protest and controversy that, by 1934, the Fleischers were pressured into toning Betty down. There is no mention in this article of the Hays Code, which also began enforcement in 1934.
Cab Calloway and His Orchestra performed their music for two other Betty Boop cartoons (both of which are also available here on IA). In Snow White, Cab sings St. James Infirmary Blues. He sings the first four verses of Minnie the Moocher for the film of the same title.
Modern cartoons are produced by recording the sound track first, and then drawing the animation afterward to synchronize with it. Early cartoons were done in reverse of that, where voice actors and music had to be more or less synced to the animation. The effect that had on the finished product is very noticeable in the early (Fleischer) Popeye cartoons, for example, especially where voice actors Billy Costello and Jack Mercer inserted soto-voiced ad libs.
However, the Fleischers were highly conscious of rhythm, as shown by their invention of the bouncing ball over the lyrics device for their Song Car-Tunes series, designed so that theater audiences could sing along. In this film, the music never stops and, by whatever methods they used to produce it, they managed to sync the animation to the rhythms so thoroughly that the entire experience becomes a dance, with every visible motion in the animation being part of it. Amazing.
Finally, I visited Tooncast's site to have a look. I found the audio there to be about the same as the audio here, but with a ton of gratuitous advertising over there. :/

When I first saw this cartoon at the age of 18, I fell in love with the music and became a bona fide fan of '20's - mid-'30's jazz. It led me to discover Bix Biederbeck, Louis Armstrong, Duke Ellington and a host of other great musicians from that era. This is my favorite Betty Boop cartoon.

From beginning to end, everything in this cartoon is just bouncing and jiving and shuffling to the beat of the music. I bet Cab loved being in it.
This has to be the most swinging cartoon ever created. Love it!

Vintage ToonCast has a version of this classic with flawless audio...

Fine!

i've seen this over 20 times and still cant get 'nuff of it..

the video portion is transferred just fine, but the audio is set to some dismally LOW level of 1 out 10, so one does NOT get to enjoy the vocal antics of beety boop or cab calloway.
I-) ihor

Another wonderful and imaginative cartoon. The music is by Cab Calloway and this cartoon features 2 tunes by Cab "Old Man Of The Mountain" and "The Scat Song".
The Fleisher organization cartoons of this period remain the gold standard of cartoons.
Stan

yeah, Nemo`s got it just right. This is a great cartoon, full of energy and imagination!

Great. Has anyone else noticed that the 'jazz' Betty Boops are much better than the 'classical' ones?
Cab Calloway is great, the beat is infectious, and Betty is so sexy that fish want her and trees fondle her ass.